Through spot pull-out destructive test, ultimate bearing capacity and slippage in the foundation slab of GFRP anti-floating anchors with different diameter were monitored. Compared with some kinds of steel anti-floating anchors in the actual engineering, their bearing performance and bond behavior were analyzed. The results showed that under the same strength and curing condition of the concrete, ultimate bearing capacity of GFRP anti-floating anchor was larger than steel anti-floating anchor with same diameter, the average bond strength between GFRP anti-floating anchor and foundation slab was higher than the steel anti-floating anchor, moreover the deformation of GFRP anti-floating anchor can meet the engineering requirements, all of those fully verify that GFRP material as an anti-floating anchor was advanced and reasonable. Based on the experimental results and theoretical analysis, the best anchoring area between GFRP anchor and foundation slab was determined, the computational formula was proposed.